What controls are there in the built in player?
A - toggle frame skipping.

P toggle ping-pong.

↵ Enter start playback (when paused).

Numpad 0 toggle looping.

Numpad . manual frame stepping.

← step back one frame.

→ step forward one frame.

↓ step back 10 frames.

↑ step forward 10 frames.

⇧ Shift+↓ use backward playback.

⇧ Shift+↑ use forward playback.

⇧ Shift hold to show frame numbers.

LMB scrub in time.

Ctrl++ zoom in

Ctrl+- zoom out

F flip image on the Y axis

Shift+F flip image on the X axis

I show frame indicator

Esc quit


Playback speed

1 NumPad 60 fps
2 NumPad 50 fps
3 NumPad 30 fps
4 NumPad 25 fps
⇧ Shift+4 NumPad 24 fps
5 NumPad 20 fps
6 NumPad 15 fps
7 NumPad 12 fps
8 NumPad 10 fps
9 NumPad 6 fps
/ NumPad 5 fps
- slow down playback.
+ speed up playback.

See also the Blender manual.